:root {
  --primary: #ff0000;
  --primary-glow: rgba(255, 0, 0, 0.4);
  --bg-dark: #0f0f0f;
  --bg-card: rgba(30, 30, 30, 0.6);
  --text-main: #ffffff;
  --text-sub: #aaaaaa;
  --glass-border: rgba(255, 255, 255, 0.1);
  --shadow-deep: 0 20px 40px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 20px var(--primary-glow);
  --radius-lg: 16px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
  background-color: var(--bg-dark);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow-x: hidden;
}

/* Subtle Noise Texture */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('https://www.transparenttextures.com/patterns/carbon-fibre.png');
  opacity: 0.05;
  pointer-events: none;
  z-index: 1;
}

.container {
  max-width: 800px;
  width: 90%;
  z-index: 2;
  text-align: center;
  padding: 40px 0;
}

/* Typography */
.hero-title {
  font-size: clamp(2.5rem, 8vw, 4.5rem);
  font-weight: 800;
  letter-spacing: -2px;
  margin-bottom: 16px;
  line-height: 1.1;
  background: linear-gradient(135deg, #fff 0%, #888 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: clamp(1rem, 3vw, 1.25rem);
  color: var(--text-sub);
  margin-bottom: 48px;
  font-weight: 400;
}

/* Input Section */
.input-group {
  position: relative;
  background: var(--bg-card);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: 8px;
  display: flex;
  gap: 8px;
  box-shadow: var(--shadow-deep);
  transition: var(--transition);
}

.input-group:focus-within {
  border-color: var(--primary);
  box-shadow: var(--shadow-deep), var(--shadow-glow);
  transform: translateY(-2px);
}

input[type="text"] {
  flex: 1;
  background: transparent;
  border: none;
  padding: 16px 24px;
  color: #fff;
  font-size: 1.1rem;
  outline: none;
}

input[type="text"]::placeholder {
  color: #555;
}

.btn-download {
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 12px;
  padding: 0 32px;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 8px;
}

.btn-download:hover {
  background: #ff3333;
  transform: scale(1.02);
  box-shadow: 0 4px 15px rgba(255, 0, 0, 0.4);
}

.btn-download:active {
  transform: scale(0.98);
}

/* Status Messages */
.status-msg {
  margin-top: 24px;
  font-size: 0.9rem;
  opacity: 0;
  transition: var(--transition);
}

.status-msg.visible {
  opacity: 1;
}

/* Preview Placeholder */
.preview-card {
  margin-top: 40px;
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: none; /* Initially hidden */
  animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Mobile Adjustments */
@media (max-width: 600px) {
  .input-group {
    flex-direction: column;
    padding: 16px;
  }
  
  .btn-download {
    height: 56px;
    justify-content: center;
  }
}

/* Modal Styles */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.85);
  backdrop-filter: blur(15px);
  -webkit-backdrop-filter: blur(15px);
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.4s ease;
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.modal-content {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: 24px;
  width: 90%;
  max-width: 550px;
  padding: 32px;
  position: relative;
  transform: translateY(40px) scale(0.95);
  transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
  box-shadow: 0 30px 60px rgba(0,0,0,0.8);
}

.modal-overlay.active .modal-content {
  transform: translateY(0) scale(1);
}

.modal-close {
  position: absolute;
  top: 20px;
  right: 20px;
  background: rgba(255, 255, 255, 0.1);
  border: none;
  color: #fff;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  font-size: 24px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

.modal-close:hover {
  background: rgba(255, 0, 0, 0.2);
  color: var(--primary);
}

.video-info {
  text-align: center;
  margin-bottom: 24px;
}

.modal-thumbnail {
  width: 100%;
  border-radius: 16px;
  aspect-ratio: 16/9;
  object-fit: cover;
  box-shadow: 0 10px 30px rgba(0,0,0,0.5);
  margin-bottom: 16px;
}

.modal-title {
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.4;
  color: #fff;
}

.download-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  max-height: 320px; /* 최대 5-6개 높이 */
  overflow-y: auto;
  padding-right: 8px;
  margin-top: 10px;
}

/* 스크롤바 커스텀 */
.download-list::-webkit-scrollbar {
  width: 5px;
}
.download-list::-webkit-scrollbar-track {
  background: rgba(255, 255, 255, 0.05);
  border-radius: 10px;
}
.download-list::-webkit-scrollbar-thumb {
  background: var(--primary);
  border-radius: 10px;
}

.download-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  transition: var(--transition);
}

.download-item:hover {
  background: rgba(255, 255, 255, 0.08);
  transform: translateX(3px);
}

.item-info {
  display: flex;
  align-items: center;
  gap: 12px;
}

.item-main-text {
  font-weight: 600;
  font-size: 0.95rem;
  color: #fff;
}

.item-sub-text {
  font-size: 0.8rem;
  color: var(--text-sub);
}

.btn-item-download {
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  border: none;
  padding: 6px 14px;
  border-radius: 8px;
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.btn-item-download:hover {
  background: var(--primary);
  box-shadow: 0 4px 12px rgba(255, 0, 0, 0.3);
}